Collaborations
We have been collaborating with universities and organizations on multiple research projects since 1999. Here are some of the projects and pending results, outlined below.
Georgia Southern University: We have worked on numerous research project with Dr. David Rostal and his graduate students at Georgia Southern University.
Sex ratios: We recorded nest incubation temperatures between 2000-2010. Sex is determined by the incubation temperature during the middle third of development ("critical period", so these temperatures are used to estimate sex ratios of hatchlings produced on the island. Using this data, it has been dtermined that the pivotal temperature for loggerheads in GA is 28.9 C (LeBlanc et al, under review). Preliminary results indicate that Wassaw and Blackbeard Islands produce an average of 30% males each year, with some cooler years approaching 40% males.
Resource Partitioning in Nesting Females: We collected 6 eggs from each of 30 nests during 2008-2010 for graduate student Ketal Patel to look at resource partitioning (variation in egg size) of nesting females throughout the season. He determined that egg size decreases throughout the season due to a decrease in albumen and yolk mass remained constant. Hatchling size also remained constant throughout the season.
Multiple Paternity: It has been shown that multiple paternity does occur in loggerhead sea turtle nests worldwide, however most sample sizes have been relatively small. We collected dead hatchlings between 2008-2010 for graduate student Jacob Lasala to determine if 1) multiple paternity occurs in Georgia’s smaller nesting population, 2) the percentage of nests displaying multiple paternity differ significantly from previous studies, and 3) the incidence of nests displaying multiple paternity vary over the course of the nesting season (early, middle and late nests). Preliminary results do support that approximately two-thirds of the nests do show paternal contributions from between 2-4 fathers, and one nest showed contributions from 7 fathers. It was also determined that the percentage of multiple paternity did not vary by season, but visual examination of the data suggests that more fathers are likely to sire individual clutches at the beginning of the summer than at the end.
University of Florida 2003-2006, 2010-present: We continue to collect adult skin biopsies and blood samples from individual turtles for stable isotope analysis to determine foraging locations and feeding levels of turtles before they returned to the nesting beach, and whether or not they feed between their nesting events.
University of Georgia 2005-present: We have been collecting data for Dr. Brian Shamblin, a geneticist at UGA, since 2005. He has been collecting adult skin biopsies and eggshells from multiple beaches from Virginia all along the coast through to the panhandle of Florida. Dr. Shamblin mapes the DNA of individual turtles from the biopsies. Then he can match the DNA of eggs taken from missed nests to females that have been previously biopsied. This data will allow us to more accurately estimate the number of females nesting in Georgia, South Carolina and North Carolina, as well as fill in some gaps in their biology (i.e. annual clutch frequency, nest site fidelity, internesting intervals, and more). So far, he has identified nests that were deposited by loggerheads originally tagged on Wassaw on Cumberland, Ossabaw and St. Catherine's Island.
Armstrong Atlantic State University 2003-2004: Dr. Kathryn Craven has been studying the potential causes of nest mortality in loggerhead sea turtle nests. We collected unhatched eggs from nests to culture and identify bacteria and fungi growing in the nests. She and her colleagues also collected and identified any ants found in the nests to document the impact of nest/ant interactions.